The present invention relates generally to computer-implemented attribute assignment determinators. More particularly, the invention relates to a computer-implemented apparatus and method for determining assignments based upon constraint optimization techniques.
Design of a system involves tradeoffs which need to be optimized. A designer seeks to embed a set of functions (e.g., optical, electromechanical, control) in an artifact or item with specified attributes (e.g., weight, color, complexity, materials, power consumption, physical size). Conflicts arise when different teams disagree on the relationship between attributes of their own functional pieces and the attributes of the entire product. Some conflicts are within the design team: how much of a mechanism""s total power budget should be available to the sensor circuitry, and how much to the actuator? Others face design off against other manufacturing functions: how should the functional desirability of an unusual machine shape be balanced against the increased manufacturing expense of creating that shape?
It is typically straightforward to represent how much a mechanism weighs or how much power it consumes, but there is seldom a disciplined way to trade-off weight and power consumption against one another. Moreover, the more attributes that are involved in a design compromise, the more difficult the trade-off becomes. The problem is the dilemma of multi-variant optimization. Analytical solutions are currently available only in specialized and limited niches. In current practice, such trade-offs are sometimes supported by processes such as QFD (Quality Functional Deployment) or resolved politically rather than in a way that optimizes the overall design and its manufacture ability.
Moreover, several current approaches use a centralized approach to optimize the overall design of a system. The centralized approach suffers several disadvantages on a number of points, including communication delays between the central decision point and the system components, and the computational complexity of decision-making over a large number of variables.
The apparatus and method of the present invention uses a novel distributed market-based constraint optimization technique to, among other things, set prices on alternative assignments to the various attributes of a design. Agents (either computerized or with human intervention) representing each component buy and sell units of these attributes. A component that needs more latitude in a given attribute (e.g., more weight) can purchase increments of that attribute from another component, but may need to sell another attribute to raise resources for this purchase. In some cases, analytical models of the dependencies between attributes may assist designers in estimating their relative cost, but even where such models are clumsy or nonexistent, prices set in the marketplace define the coupling among the attributes.
The apparatus and method of the present invention make assignments to attributes of components within a system. The attributes have variables indicative of assignments to the attributes. A first constraint data structure is used for determining a preferential set of assignments to a first variable. The first variable is indicative of an assignment to a first attribute of a first component. The first constraint data structure has first preferential rules for determining preferential assignments to the first variable. A first computer module is connected to the first constraint data structure for determining bid data based upon the first preferential rules. The bid data contains price data associated with a first preferential set of assignments to the first variable. The first variable is assigned a value based upon the bid data.
For a more complete understanding of the invention, its objects and advantages, reference may be had to the following specification and the accompanying drawings.